Plasma crashes in Kubuntu 15.04

Application: Plasma (plasmashell), signal: Aborted
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[Current thread is 1 (Thread 0x7f2b806597c0 (LWP 2975))]

Thread 5 (Thread 0x7f2b6c1cf700 (LWP 2979)):
#0 0x00007f2b7b3bb8dd in poll () at ../sysdeps/unix/syscall-template.S:81
#1 0x00007f2b7d949b72 in ?? () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#2 0x00007f2b7d94b64f in xcb_wait_for_event () from /usr/lib/x86_64-linux-gnu/libxcb.so.1
#3 0x00007f2b6e593099 in ?? () from /usr/lib/x86_64-linux-gnu/qt5/plugins/platforms/libqxcb.so
#4 0x00007f2b7ba43b0e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5 0x00007f2b7ac3f6aa in start_thread (arg=0x7f2b6c1cf700) at pthread_create.c:333
#6 0x00007f2b7b3c6eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 4 (Thread 0x7f2b5ec57700 (LWP 2994)):
#0 0x00007f2b77aae789 in g_mutex_lock () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#1 0x00007f2b77a69409 in g_main_context_prepare () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f2b77a69de8 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007f2b77a69fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007f2b7bcdac6c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#5 0x00007f2b7bc7f3e2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6 0x00007f2b7ba3eb44 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7 0x00007f2b7d7e1f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#8 0x00007f2b7ba43b0e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9 0x00007f2b7ac3f6aa in start_thread (arg=0x7f2b5ec57700) at pthread_create.c:333
#10 0x00007f2b7b3c6eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 3 (Thread 0x7f2b4ffff700 (LWP 3018)):
#0 pthread_cond_wait@@GLIBC_2.3.2 () at ../sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:185
#1 0x00007f2b5771d4fb in ?? () from /usr/lib/x86_64-linux-gnu/dri/r600_dri.so
#2 0x00007f2b5771cc87 in ?? () from /usr/lib/x86_64-linux-gnu/dri/r600_dri.so
#3 0x00007f2b7ac3f6aa in start_thread (arg=0x7f2b4ffff700) at pthread_create.c:333
#4 0x00007f2b7b3c6eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 2 (Thread 0x7f2b4e7df700 (LWP 3019)):
#0 0x00007f2b7b3b749d in read () at ../sysdeps/unix/syscall-template.S:81
#1 0x00007f2b77aad2f0 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007f2b77a6996c in g_main_context_check () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007f2b77a69e60 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007f2b77a69fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007f2b7bcdac6c in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#6 0x00007f2b7bc7f3e2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#7 0x00007f2b7ba3eb44 in QThread::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#8 0x00007f2b7d7e1f65 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5
#9 0x00007f2b7ba43b0e in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#10 0x00007f2b7ac3f6aa in start_thread (arg=0x7f2b4e7df700) at pthread_create.c:333
#11 0x00007f2b7b3c6eed in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109

Thread 1 (Thread 0x7f2b806597c0 (LWP 2975)):
[KCrash Handler]
#6 0x00007f2b7b2f5267 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#7 0x00007f2b7b2f6eca in __GI_abort () at abort.c:89
#8 0x00007f2b7ba30edf in QMessageLogger::fatal(char const*, ...) const () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#9 0x000000000045ddf6 in ShellManager::updateShell() ()
#10 0x000000000045e8c7 in ShellManager::loadHandlers() ()
#11 0x0000000000479efd in ?? ()
#12 0x00007f2b7bcb373a in QObject::event(QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#13 0x00007f2b7c593b2c in QApplicationPrivate::notify_helper(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#14 0x00007f2b7c599000 in QApplication::notify(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Widgets.so.5
#15 0x00007f2b7bc81c2b in QCoreApplication::notifyInternal(QObject*, QEvent*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#16 0x00007f2b7bc83c9b in QCoreApplicationPrivate::sendPostedEvents(QObject*, int, QThreadData*) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#17 0x00007f2b7bcda843 in ?? () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#18 0x00007f2b77a69c3d in g_main_context_dispatch () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#19 0x00007f2b77a69f20 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#20 0x00007f2b77a69fcc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#21 0x00007f2b7bcdac57 in QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#22 0x00007f2b7bc7f3e2 in QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#23 0x00007f2b7bc8702c in QCoreApplication::exec() () from /usr/lib/x86_64-linux-gnu/libQt5Core.so.5
#24 0x000000000042fd9b in main ()